Process for the continuous distillation of glycerin from the weak glycerinous liquors obtained in fermentation processes



E. A. BARBET.

PROCESS FOR THE CONTINUOUS DISTILLATION OF GLYCERINE FROM THE WEAK GLYCERINOUS LIQUORS OBTAINED IN FERMENTATION PROCESSES.

APPLICATION F|LED]UNE25,1919. 1 ,Q1 6,3186 Patented May 16, 1922.

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EMILE AUGUSTIN BARBIE-T, OF PARIS, FRANCE.

PROCESS FOR THE CONTINUOUS DISTIL-LATION OF GLYCERIN FRbM THE WEAK GLYCERINOUS LIQUORS OBTAINED IN FERMENTATION PROCESSES.

Application filed June 25, 1919.

To all whom it may concern Be it known that I, EMILE AUGUsTiN BARBET, a citizen of the French Republ c, residing at No. 5 Rue de lEchelle, Paris, France, have invented certain new and useful Improvements in the Process for the Continuous Distillation of Glycerin from the Weak Glycerinous Liquors Obtained in Fermentation Processes, of which the following is a specificatiqn.

This invention has for its object to provide an improved process for the continuous distillation of glycerin for the purpose of extracting the same from the glycerin containing liquors obtained infermentation processes.

The present invention consists in effecting the distillation of the glycerinous syrup in a systematic and continuous manner, whereby the glycerin is extracted with a smaller consumption of carrying-over steam.

In order to secure great economy, the preliminary concentration of the weak alcoholic liquors must be effected by employing numerous successive effects of the steam and by means of apparatus which are at one and the same time easy to clean with a brush, and which are so constructed as to retain the scum and froth carried over.

After this first continuous concentration by multiple effect which must be carried up to at least a density of 1.25, the glycerlnous syrup is passed into the improved continuous apparatus shown in the accompanying draw- The improved apparatus comprises a final concentration apparatus A and an apparatus B for carrying over the glycerin.

1. Final concmufmtiom-The final concentration must be carried to a very high point, in fact until almost the whole of the water is removed. This may be done, even continuously, in an evaporating apparatus A provided that it is heated with hot steam, and that there is an active circulation of the syrup in the tubes with the provision of a safety vessel A of large diameter for preventing the bubbles or froth belng carried over.

2. Carrying 0oer'.The syrup which is almost anhydrous, drawn from the cook a, feeds continuously the carrying-over column B by way of the pipe a -This column s composed of a few double-walled cylindrical sections, with a cover and a bottom boiler.

Specification of Letters Patent.

Patented May is, 1922.

Serial N0. 306,620.

The latter contains a live steam (at least fiye atmospheres) worm V, and a coil of pipes provided with perforations o by means of which superheated steam is injected into the liquid.

In the-base of each of the sections there are situated plates with overflows, which may be composed of perforated metal plates or plates with hoods. The perforated plate 1s more practical because each plate must have a live steam worm 0 designed to maintain the glycerinous syrup at the maximum temperature.

The sections must be of fairly considerable height in order to prevent the scum or froth from rising from one plate to the other. I

The vapours issuing from the top of B pass through the pipe b to a powerful cooler-condenser C of the tubular or of the worm type. In the separator a situated at the exit of C, the gylcerinous liquid separates and descends by barometric pressure into the vessel N through the pipe n, whilst the Water vapour or steam and the gases pass through the pipe 0 into. the baromet I temperature of 180 C. on the plates B, but

also that the steam passing from plate to plate shall remain superheated, and finally that no condensation of glycerin upon the walls shall be permitted to take place. F or this purpose the walls are coated with good non-conducting materials. It is however preferred to construct the sections of the column with double walls and to circulate very hot steam through the space between the inner and outer Walls.

The glycerinous vapour given off from the top plate will contain a proportion of glycerin depending on the strength of the glycerinous syrup. Unfortunately, however, owing to the numerous impurities in the weak alcoholic liquors, there is always a relatively poor syrup to be dealt with. such syrup being much poorer than the soap making lyes or soap lyes. It is for this reason that continuity is valuable, as in the intermediate working the initial percentage strength traction.

It is to be' understood that when only 1% of glycerin is left, it will require a very con siderable consumption of superheated steam to carry off the last portions, whereas on the contrary in continuous working the steam will always pass out from the top atthe maximum.

The continuous discharge of the exhaust-ed material, which readily solidifies immediately the temperature drops, presents a real difiiculty. It cannot be extracted by means; of a pump.

In the apparatus shown in the accompany ing drawing the discharge of the exhausted material is 'elfected by barometric pressure, the column B being placed on a sufliciently high floor for this purpose. The discharge is regulated by the valve 6, and in order that the material shall not set in descending, the down pipe H is surrounded by a second pipe H through which passes very hot steam. The syrup thus falls into a trough K forming a barometric tank which is provided with a steam worm L. The trough K discharges by means of an overflow into movable metal gutters m which are cooled by the flowing water of a trough M. The material sets; it is then broken up for use as a manure.

Gr is the barometric tank of the condenser D which is supplied with cold water through the pipe d provided with a regulating cock. The vacuum is produced either by means of a dry air pump E or by means of a high power vacuum ejector and is with advantage Lemme maintained in the neighbourhood of 40 to 60 mm. of mercury column.

What I claim is.:

1. The process for the extraction of glycerin from dilute glycerinous liquors, which consists in subjecting continuously the previously concentrated weak glycerinous liquors to a further concentration, under reduced pressure, in a rapid-circulation evaporator, subjecting the resulting syrup whilst it is maintained at a high temperature andunder reduced pressure repeatedly to the action of a current of superheated steam, condensing the resulting vapours, separating the glycerino-us liquid from the gases and wa ter vapour or steam and effecting the discharge of the exhausted material through an externally heated discharge device.

2. Process for extracting glycerin from dilute glycerinous liquors, which consists in subjecting the previously concentrated weak glycerinous liquors to a further concentration in an evaporator having a rapid circu lation and energetic heating, bringing the resulting syrup into a column apparatus provided with bubbling plates wherein the liquid is maintained at a high temperature and under reduced pressure, subjecting the descending syrup to the action of ascending current of superheated steam, condensing the resulting vapours, separating the glycerinous liquid from the gases and water vapour, and effecting the discharge of the exhausted material in a liquid state.

In testimony whereof I havesigned my name to this specification.

EMILE AUGUSTIN BARBET. 

